The addition of cyanide to activated olefins is a well-known reaction. The preparation of polycyano compounds by the hydrocyanation and subsequent hydrolytic decarboxylation of .alpha.-cyanoacrylates was first proposed by D. T. Mowry, J. Am. Chem. Soc., 68, 2108 (1946). He proposed a one-step process wherein the hydrocyanated ester intermediate was formed and then decarboxylated all in one reaction vessel without intermediate purification steps. The yield obtained (77 percent crude yield) was improved over the yields of earlier reported syntheses. The reference employed an 80 percent molar excess of cyanide.